A sealing device includes a fixture that encloses a target to be sealed, and a sealing key that locks the fixture. To unseal the sealing device, the sealing key has to be destroyed. Therefore, it is possible to distinguish whether or not fraudulent substitution or fraudulent unsealing of the target has been conducted by a third party.
For example, PTL 1 discloses a sealing tool that includes a body that rotatably supports a U-shaped arm for sealing a target to be sealed, and a lock key that releases locking by being destroyed. PTL 2 discloses a sealing device that includes a fixture provided to fix a slider of a fastener, and a sealing key that releases locking by being destroyed.
The sealing device as mentioned above requires a means for sensing destruction of the sealing key by a method other than visual inspection. As a sealing device that includes such a detecting means, PTL 3, for example, discloses a technique in which the sealing key described in PTL 2 is further incorporated with an IC tag. A signal originating from the IC tag is detected by a detector through non-contact communication. When the sealing device is unsealed, the sealing key is destroyed and at the same time an antenna of the IC tag is also destroyed, and thereby unsealing of the sealing device is detected.